Determining the Rayleigh damping parameters of flexible pavements for finite element modeling

2021 ◽  
pp. 107754632110267
Author(s):  
Jiandong Huang ◽  
Xin Li ◽  
Jia Zhang ◽  
Yuantian Sun ◽  
Jiaolong Ren
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Natural Frequencies ◽  
Least Squares Method ◽  
Element Model ◽  
Beam Model ◽  
Element Modeling ◽  
Rayleigh Damping ◽  
Damping Matrix

The dynamic analysis has been successfully used to predict the pavement response based on the finite element modeling, during which the stiffness and mass matrices have been established well, whereas the method to determine the damping matrix based on Rayleigh damping is still under development. This article presents a novel method to determine the two parameters of the Rayleigh damping for dynamic modeling in pavement engineering. Based on the idealized shear beam model, a more reasonable method to calculate natural frequencies of different layers is proposed, by which the global damping matrix of the road pavement can be assembled. The least squares method is simplified and used to calculate the frequency-independent damping. The best-fit Rayleigh damping is obtained by only determining the natural frequencies of the two modal. Finite element model and in-situ field test subjected by the same falling weight deflectometer pulse loads are performed to validate the accuracy of this method. Good agreements are noted between simulation and field in-situ results demonstrating that this method can provide a more accurate approach for future finite element modeling and back-calculation.

Vibration Response of a Thin-Walled Cylindrical Pipe with Liquid

2012 ◽  
Vol 189 ◽  
pp. 345-349
Author(s):  
Yu Lan Wei ◽  
Bing Li ◽  
Li Gao ◽  
Ying Jun Dai
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
Beam Model ◽  
Vibration Modes ◽  
Timoshenko Beam Model ◽  
Cylindrical Pipe ◽  
Bending Vibration ◽  
Beam Bending ◽  
Thin Walled

Vibration characteristics of the thin-walled cylindrical pipe are affected by the liquid within the pipe. The natural frequencies and vibration modes of the pipe without liquid are analyzed by the theory of beam bending vibration and finite element model, which is based on the Timoshenko beam model. The first three natural frequencies and vibration modes of the pipe with or without liquid are acquired by experiments. As shown in the experiment results, the natural frequencies of the containing liquid pipe are lower than the natural frequencies of the pipe without liquid.

Experimentally validated predictive finite element modeling of the V0-V100 probabilistic penetration response of a Kevlar fabric against a spherical projectile

2018 ◽  
Vol 9 (4) ◽  
pp. 504-524 ◽  
Author(s):  
Gaurav Nilakantan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Woven Fabric ◽  
Projectile Impact ◽  
Element Modeling ◽  
The Impact

This work presents the first fully validated and predictive finite element modeling framework to generate the probabilistic penetration response of an aramid woven fabric subjected to ballistic impact. This response is defined by a V0-V100 curve that describes the probability of complete fabric penetration as a function of projectile impact velocity. The exemplar case considered in this article comprises a single-layer, fully clamped, plain-weave Kevlar fabric impacted at the center by a 0.22 cal spherical steel projectile. The fabric finite element model comprises individually modeled three-dimensional warp and fill yarns and is validated against the experimental material microstructure. Sources of statistical variability including yarn strength and modulus, inter-yarn friction, and precise projectile impact location are mapped into the finite element model. A series of impact simulations at varying projectile impact velocities is executed using LS-DYNA on the fabric models, each comprising unique mappings. The impact velocities and outcomes (penetration, non-penetration) are used to generate the numerical V0-V100 curve which is then validated against the experimental V0-V100 curve obtained from ballistic impact testing and shown to be in excellent agreement. The experimental data and its statistical analysis used for model input and validation, namely, the Kevlar yarn tensile strengths and moduli, inter-yarn friction, and fabric ballistic impact testing, are also reported.

scholarly journals Finite Element Modeling and Mechanical Behavior of Masonry-Infilled RC Frame

2016 ◽  
Vol 10 (1) ◽  
pp. 76-92
Author(s):  
Hongyu Deng ◽  
Baitao Sun
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Element Model ◽  
Simulation Method ◽  
Shear Resistance ◽  
Calculation Formula ◽  
Infill Wall ◽  
Seismic Code ◽  
Element Modeling ◽  
Contact Position

During the analysis of reinforced concrete structures, the infill wall is usually simplified as a diagonal inclined strut to facilitate finite element modeling calculations. However, the actual seismic damage and single frame-filled wall pushover experimental results show that when the earthquake shear force is huge, the top of the infill wall and the beam–column connections are usually, thus the path of the force transfer will be changed. Based on this actual failure phenomenon, a new calculation model which has different contact position between the equivalent bracing walls and the frame columns is generated. Thus, the force analysis is given based on this model, the formulae for calculating the equivalent width of bracing walls, the shear bearing capacity of the wall-filled frame, and the infill wall’s actual participation in the stiffness. A finite element simulation method by ABAQUS is used to determine an empirical formula for calculating the reasonable contact position between the equivalent bracing walls and the frame columns. The verification results show that the finite element model presented in this paper is more reasonable, and the stiffness and shear resistance of infill wall should not be neglected. The calculation formula of stiffness of infill wall presented in this paper is coincided with seismic code. But the calculation formula of shear resistance of infill wall presented in seismic code is higher than the actual value, so it is suggested that calculation formula presented in this paper should be accepted.

Development of the Finite Element Modeling Markup Language

2002 ◽  
Author(s):  
J. G. Michopoulos
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Element Model ◽  
Data Interpretation ◽  
Markup Language ◽  
Document Type ◽  
Element Modeling ◽  
Type Definition ◽  
Extensible Markup ◽  
Modeling Data

The finite element modeling Markup Language (femML) effort is addressing the problems of data interpretation and exchange for intra- and inter- application interoperability in the Finite Element Modeling domain. This is achieved through the development of an extensible markup language (XML) variant for finite element model data that will permit the storage, transmission, and processing of finite element modeling data distributed via the World Wide Web and related infrastructure technologies. The focus of this work was to utilize the XML’s power of semantic encapsulation along with the existing and continuously improving associated technology to develop a dialect for exchanging FEM data across various codes with heterogeneous input format syntactic specifications. The main aspects of a finite element definition have been used as archetypes for defining the XML element taxonomy definitions. Namely, the geometry, the material, and the loading aspects of a structural component specification are used to define the first level elements of the associated Document Type Definition (DTD). The element list has been amended with a behavior element specification that represents the solution data to be exchanged or visualized. Various tools have been developed to demonstrate associated concepts along with the ANSYS set of tools.

2D Meso-Scale Finite Element Modeling and Simulation of Polymer-Mineral Composite Material

2016 ◽  
Vol 848 ◽  
pp. 3-8
Author(s):  
Pei Yao Sheng ◽  
Shi Zhao Wang ◽  
Zhong Ji
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Numerical Analysis ◽  
Finite Element Modeling ◽  
Epoxy Resin ◽  
Element Model ◽  
Fe Model ◽  
Element Modeling ◽  
Low Thermal Expansion ◽  
Meso Scale

Polymer-mineral composite material is prepared by using modified epoxy resin as binder and mineral particles as aggregates. Its excellent damping characteristic and low thermal expansion make it ideal in manufacturing machine tool beds. However, the properties of this material depend on its formula and structure, so it is very important to develop an efficient method to numerically model the materials and then to optimize their properties. In this paper, 2D meso-scale finite element modeling is presented for numerical analysis of the mechanical properties of polymer-mineral composite material. The material was treated as a 2-phase composite composed of aggregates and binder which was epoxy resin mixed with fillers. Based on grading curve, the weights of aggregates were converted into the corresponding area, the aggregate particles were randomly generated and assembled with binder to produce the model. And then 2D numerical simulations were conducted under different gradations. The results show that: (1) the 2D FE model is very close to the real polymer-mineral composite material in the aspect of density and aggregate shapes and sizes, which validate the fidelity of the generated finite element model and numerical analysis method; (2) by comparing the materials’ properties under four different gradations, it can be found that the materials with SAC gradation have the best mechanical property.

BOUNDARY CONDITIONS IN FINITE ELEMENT MODELING OF STRATIFIED COASTAL CIRCULATION

1988 ◽  
Vol 1 (21) ◽  
pp. 190
Author(s):  
George C. Christodoulou ◽  
George D. Economou
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Coastal Waters ◽  
Stratified Flow ◽  
Element Model ◽  
Numerical Computations ◽  
Element Modeling ◽  
Sponge Layer

The effect of boundary conditions on numerical computations of stratified flow in coastal waters is examined. Clamped, free radiation and sponge layer conditions are implemented in a two-layer finite element model and the results of simple tests in a two-layer stratified basin are presented.

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